Introducing Flow CI Engine

At Flow, we’ve always believed that the best infrastructure is the one you never have to think about. When we first launched Mac Bare Metal, our goal was simple: to give developers direct access to high-performance Apple Macs in the cloud. Over the years, this service has become the backbone for hundreds of teams building, testing, and shipping apps for the Apple ecosystem—iOS, macOS, watchOS, visionOS, and tvOS.

But we never stopped listening. We spoke with indie developers struggling to maintain CI pipelines. We met DevOps engineers juggling macOS image management. We sat down with startups scaling rapidly—and enterprise teams craving more simplicity. And that’s how Flow CI Engine was born.

Goodbye Infrastructure Headaches, Hello Fully Managed CI

Think of Flow CI Engine as the spiritual successor to Mac Bare Metal. It’s everything you loved about direct access to real Mac hardware—but now elevated to a fully managed platform. We took care of everything under the hood. No more wrangling with macOS templates, no more configuring your build environment from scratch, no more worrying about compliance with Apple’s licensing terms.

With Flow CI Engine, you can focus on shipping code—not managing infrastructure.

Pre-Configured. Customizable. Lightning Fast.

At launch, CI Engine offers golden macOS images with essential developer tools baked in—ready to use, globally available, and constantly updated by us. Need something more specific? No problem. Our Professional Plan lets you build and manage your own custom images right on the platform. We’ll handle the distribution and maintenance for you. No local scripts. No manual updates. Just version-controlled, repeatable environments at your fingertips.

Blazing Performance

One thing we knew from the start: performance matters. That’s why every macOS VM runs directly on the local NVMe disks of our M4 Pro Mac minis—no shared network storage, no bottlenecks. This means maximum disk I/O, consistent performance, and build times that only get better as Apple’s hardware evolves.

Plug & Play with Your Existing Pipelines

We made sure CI Engine fits seamlessly into your existing workflows. At launch, we support integrations with GitHub Actions and Buildkite—with GitLab coming soon. Setup takes just a few minutes, and from there, your builds run on real Macs with all the benefits of our platform.

100% Carbon Neutral. Seriously.

This part makes us especially proud. Flow CI Engine is powered by Apple’s new M4 Pro Mac minis—the first carbon-neutral Macs ever made. But we didn’t stop there. These machines run in a Swiss data center that’s fully carbon neutral, cooled using local lake water, powered by Swiss hydropower, and feeding excess heat back into the nearby town. Even our uninterruptible power supply is sustainable—using kinetic energy from flywheels instead of batteries.

So when we say 100% Carbon Neutral, we mean it—from silicon to software.

Simple Pricing. No Headaches.

Our pricing is just as streamlined as the platform itself. You pay based on how many concurrent build jobs you need. That’s it. Unlimited build jobs. No confusing compute credits. No surprise bills. Whether you’re a solo developer or a team of 50, there’s a plan that fits.

This Is Just the Beginning

Flow CI Engine is more than just a product. It’s the result of years of learning, building, and obsessing over what developers actually need from their Mac CI infrastructure. Mac Bare Metal isn’t going anywhere—it still has its place for teams that want full control over the machine. But for everyone else who just wants builds that work, scale, and stay out of the way, Flow CI Engine is here.

Ready to give it a try? Request your invite.